[pero81]

Hello all, I have a problem with my servo and hope someone can help me. First of all let me introduce my system. I use Mach3 with DSPMC/IP motion controller and servo drive (sidc650) with motor (sia751). I have setup my drives in velocity control mode because I can get better resaults from it and it is more stable. Now on to the problem. When I turn on the power and want to move any of the axis for a few milimeters motor accelerates slowly with constant speed. But when I move axis longer than few milimeters motor jumps hard and then everything is working normal. All motors are working well without any problem. This problem appears on every axis (x,y,z) every time drives are powered ON/OFF. If I set drives in torque mode, motors start to spin withaut any problems even if drives are turn on/off. I just can't figure out what is causing that problem. Also I'm attaching pdf manual of drives and I made some videos about this problem.

[ame=http://www.youtube.com/watch?v=Mhr8beADhjU]1.AVI - YouTube[/ame]
[ame=http://www.youtube.com/watch?v=fmQ71kvrvU4]2.AVI - YouTube[/ame]
[ame=http://www.youtube.com/watch?v=TONOXsU1els]3.AVI - YouTube[/ame]

Here are my curent settings for y axis

PN01 0002 (velocity control mode)
PN08 0000
PN10 1500
PN11 1000 MAX acceleration
PN15 -5
PN16 5
PN17 32 SPEED SCALE
PN20 60000
PN25 2000 FOLLOW ERROR
PN30 P 1000
PN31 D 000
PN32 I 000
PN33 00 DAMPER
PN35 720 Forward velocity compensation

Regards,
Peter

[pero81]

Anybody please?

Peter

[acondit]

Peter,

I really don't know, but I would try going back to the beginning and retuning the drive starting on pg 45. I looks almost like a jump to catch up with something.

What kind of encoder are you using? Someone reported seeing something like what you are seeing with capacitive encoders.

Alan

[pero81]

Thank you very much for answer Alan. It's 5V, 2500PPR quadrature encoder. It is original encoder. I even took all motors to service company to make sure that all signals are working and if the commutative pulses (U,W,V) are set right. Strange thing also is when I turn power on and manualy jog motors from drive and then switch to velocity control it works with no problem. This problem apears only when power is turn on and try to move motors with velocity control mode.

Regards,
Peter

[keebler303]

If the motor is stationary and you instantly command it to be going 500 RPM (for example) then the drive will supply peak current to the motor to get it to 500 RPM as quickly as possible. I'm not familiar with your hardware but it would seem you need to adjust some settings.

Matt

[pero81]

Hello Matt, I think I've tried everything I can think of. I realy dont know what else to do. I will probably start thinking to buy some better drives and motors because of this problem and bad performance in torque mode or voltage mode.

Peter